1. Technical Field
The present invention relates to a liquid ejecting head unit provided with a plurality of liquid ejecting heads capable of ejecting a liquid from nozzle openings and a method of manufacturing the same.
2. Related Art
A liquid ejecting apparatus of which a representative example is an ink jet printing apparatus such as an ink jet printer or a plotter includes a liquid ejecting head unit (hereinafter, also referred to as a head unit) provided with liquid ejecting heads capable of ejecting a liquid such as ink stored in a cartridge or a tank in the form of liquid droplets.
The plurality of liquid ejecting heads are placed on a platform as a common supporting member so as to be arranged in line. In addition, the plurality of liquid ejecting heads are continuously arranged in an arrangement direction of nozzle rows in which nozzle openings of each of the liquid ejecting heads are arranged (for example, JP-A-5-57965 and JP-A-2000-25207).
Here, in the liquid ejecting head unit including the plurality of liquid ejecting heads, liquid ejecting methods such as a method of allowing the plurality of liquid ejecting heads to eject different kinds of liquids or a method of allowing the plurality of liquid ejecting heads to eject a common liquid are required to be individually selected depending on uses of the liquid ejecting apparatus mounted with the liquid ejecting head unit.
In order to change the liquids ejected by the plurality of liquid ejecting heads, a liquid storage unit storing the liquids supplied to the liquid ejecting heads may be changed. However, since the change in the liquid storage unit are accompanied with specification change in the size, the number, arrangement, or the like of the liquid storage unit of the liquid ejecting apparatus, problems with complication and high cost may be caused.
In particular, in the liquid ejecting apparatus including a large liquid ejecting head unit, the specification change in the liquid storage unit is complicated. Therefore, it is necessary to provide a switching member capable of changing flow passages in a simple manner and at low cost.
There was suggested a printing apparatus which has a connection switching member, which is capable of changing a connection relation between a plurality of ink tanks and a plurality of nozzle rows, in an ink supply unit between the nozzle rows and the ink tanks storing ink formed in an ink jet print head (for example, see JP-A-2003-237100).
In the configuration of the printing apparatus disclosed in JP-A-2003-237100, however, a plurality of nozzle rows are just provided in one ink jet print head, no stem flow passage commonly formed in the plurality of ink jet print heads is provided, and no switching member capable of changing the flow of a liquid flowing in a branch flow passage connecting a stem flow passage to the ink jet print head is provided. When the plurality of ink jet print heads and a stem flow passage common to the plurality of ink jet print heads are provided, the size of the head unit becomes large. Therefore, problems occur in that the replacement or modification of the stem flow passage may particularly be complicated and specification modification of the storage unit may be also complicated.
Moreover, theses problems occur not only in the ink jet print head unit having the ink jet print head ejecting ink, but also in a liquid ejecting head unit having a liquid ejecting head ejecting a liquid other than ink.